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a) Since you gave your employer two weeks advance notice, your employer was required to give you your final check, including your PTO on the last day that you worked.
You are entitled to a day's wages per day that you were required to receive the money due to you. This only includes business days and not holidays, including Christmas and New Year's.
b) Yes, this is the status of the law. However, this is a law "without any teeth," meaning that there is no punishment against your employer for failing to adhere to this law.
c) If you haven't been paid the full amount due to you then you would be entitled to 30 days of wages as a maximum penalty against your employer. (Technically, this is a penalty and is not considered 'back wages.' You would only be due this penalty and not additional 'back wagess' for your employer's violations of the labor ocde.)
If your employer does not comply with the law, you should file a wage claim against your employer with the Department of Labor.
You can do so using the forms available online here:http://www.dir.ca.gov/dlse/howtofilewageclaim.htm